European legislation based on the New Approach requires that technical requirements for products are given in harmonised European standards. The Directive 89/686/EEC on Personal Protective Equipment came into force in 1995. The existence of product and testing standards is a prerequisite for the effective implementation of the directive. There was a need to develop several standards in a very short time period and the basic standards for hearing protectors have already been revised once. It is important to continue the validation of the standardized testing methods and requirement levels. This requires good co-operation and research between test laboratories and research institutes, especially as it is necessary to ensure new products comply with these technical requirements.
Keywords: Standardisation, testing, certification, directive, hearing protector, noise
|How to cite this article:|
Korhonen E. European standardisation of hearing protectors. Noise Health 2005;7:55-8
| Introduction|| |
According to a study entitled European Foundation for the Improvement of Living and Working Conditions, 28 per cent of workers are exposed to loud noise (Paoli and Damien, 2000). It suggests exposure can be prevented or controlled by technical or organizational means. If this is not possible, the remaining risk can be controlled by providing workers with suitable personal protective equipment. Hearing protectors play an important role in reducing daily exposure to accepted limit values. It is vital that products on the market really provide the protection that the user requires. In addition to the protection efficiency, usability and comfort are other factors that need to be taken into account. The technical requirements for hearing protectors therefore specify an optimum level of protection leading to maximum efficiency while taking into account usage rates. This review aims to describe the basic requirements of the European standards for hearing protectors concerning testing, use, selection and maintenance.
| Requirements|| |
The requirements for the design and manufacture of Personal Protective Equipment (PPE) are laid down in European Directive 89/686/EEC of 21 December 1989. These requirements contain only essential safety aspects.
The basic requirement for PPE used against the harmful effects of noise is:
PPE designed to prevent the harmful effects of noise must be capable of attenuating the latter to such an extent that the equivalent sound levels perceived by the user do not under any circumstances exceed the daily limit values laid down by Council Directive 86/188/EEC of 12 May 1986 on the protection of workers from the risks related to exposure to noise at work All PPE must bear labeling indicating the noise attenuation level and the value of the comfort index provided by the PPE; should this not be possible, the labeling must be fixed to the packaging.
In addition some general requirements for PPE are given: the PPE shall not create other risks or harmful effects for the user; it shall be made of materials which are safe and do not cause skin problems; all parts of a hearing protector in contact with the user shall have suitable surfaces without sharp edges or other harmful features.
A second EC Directive relevant to hearing protectors is Council Directive 89/656/EEC of 30 November 1989 concerning the use of PPE by workers at their workplaces. This directive contains an employer's obligations including the need to carry out a risk analysis, which is the basis for the subsequent selection of the correct PPE. Also a Commission Communication assesses the safety aspects when choosing and using personal protective equipment (89/C 328/02). As good protection efficiency may in some cases lead to poorer communication and wearer comfort, specific guidelines for the selection and use of hearing protectors have been elaborated and published as European standard EN 458.
| Standardization|| |
There are European and international standards for hearing protectors. In Europe, CEN/TC 159 (European Committee for Standardization, Technical Committee 159, Hearing Protectors) is responsible for the standardization but the acoustical test methods are set out by ISO/TC 43/SC1 (International Organization for Standardization, Technical Committee 43, Acoustics, Sub-Committee 1, Noise). Working Group 17 is drafting measurement methods for sound attenuation of hearing protectors. The standards created in ISO are implemented by CEN/TC 211, Acoustics.
The following standards are produced by CEN Technical Committee EN/TC 211, Acoustic.
- EN ISO 4869-2:1995, Acoustics - Hearing protectors - Part 2: Estimation of effective A weighted sound pressure levels when hearing protectors are worn (ISO 4869-2:1994)
- EN 24869-3:1993, Acoustics - Hearing protectors - Part 3: Simplified method for the measurement of insertion loss of ear-muff type protectors for quality inspection purposes (ISO/TR 4869-3:1989)
- EN ISO 4869-4:2000, Acoustics - Hearing protectors - Part 4: Measurement of effective sound pressure levels for level-dependent sound restoration ear-muffs (ISO/TR 4869-4:1998)
- EN 24869-1:1992, Acoustics - Hearing protectors: Subjective method for the measurement of sound attenuation (ISO 48691:1990)
- prEN ISO 4869-5, Acoustics: Measurement of performance characteristics of hearing protectors in impulsive noise [still under development]
CEN Technical Committee 159 has the following active working groups:
TC 159 has produced the following harmonised European standards:
- WG 2, Amplitude sensitive hearing protectors
- WG 5, Guidance document for hearing protectors
- WG 6, General requirements and test methods
- Recommendations for selection, use, care and maintenance - Guidance document
- EN 352-1:2002, Hearing protectors - General requirements - Part 1: Ear-Muffs
- EN 352-2:2002, Hearing protectors - General requirements - Part 2: Ear-plugs
- EN 352-3:2002, Hearing protectors - General requirements - Part 3: Ear-muffs attached to an industrial safety helmet
- EN 352-4:2001, Hearing protectors - Safety requirements and testing - Part 4: Leveldependent ear-muffs. [This part describes a different test method from that set out as EN ISO 4869-4 for the same product. Based on the studies and published test results, the test procedures will give different results. The recommendation of the European co-operation group is to use the method described in standard EN 352-4.]
- EN 352-5:2002, Hearing protectors - Safety requirements and testing - Part 5: Active noise reduction ear-muffs
- EN 352-6:2002, Hearing protectors - Safety requirements and testing - Part 6: Ear-muffs with electrical audio input
- EN 352-7:2002, Hearing protectors - Safety requirements and testing - Part 7: Leveldependent ear-plugs
- EN 13819-1:2002, Hearing protectors - Testing - Part 1: Physical test methods * EN 13819-2:2002, Hearing protectors - Testing - Part 2: Acoustic test methods
- EN 458:1993, Hearing protectors
Parts 1, 2 and 3 of EN 352 cover the performance of functions in passive hearing protectors while the remaining Parts cover the performance of functions additional to passive hearing protection. Hearing protectors which incorporate one or more of these functions are subject to the requirements and tests of each of the relevant Parts of EN 352, including Parts 1, 2 and 3. An associated standard, EN 458, covers the selection, use, care and maintenance of hearing protectors.
The standards call for the values of sound attenuation afforded by the protector to be measured in accordance with EN 24869-1.
The following new work items are still under development:
- prEN 352-8, Hearing protectors - Safety requirements and testing - Part 8: Ear-muffs with entertainment audio input
- prEN 352-9, Hearing protectors - Safety requirements and testing - Part 9: Ear-plugs with electrical audio input
- prEN 352-10, Hearing protectors - Safety requirements and testing - Part 10: Ear-plugs with entertainment audio input
| Common understanding|| |
Products marketed in Europe must be CE certified. The conformity assessment is made by competent laboratories nominated by authorities of the member states. A committee for the coordination of notified bodies deals with questions relating to the implementation of any PPE Directive. For each type of PPE, a Vertical Group is created.
The recommendations of Vertical Group 4 (hearing protectors) of the co-ordination of the notified bodies should also be taken into account in the conformity assessment. The aim of these recommendations is to clarify the text used in the standards so as to increase common understanding of the test methods. As well, inter laboratory tests are organized, including the current issue which is to study the uncertainty of measurements. Important tools in this aspect are "round robin" tests.
| Future activities|| |
Adopted EN standards have served as a reference for CE certification of hundreds of hearing protectors. These are under constant evaluation and a review is made at least every five years. Due to limited resources, the validation of the test methods, especially for electronic hearing protectors, is still lacking. There is also limited co-operation between test laboratories creating a problem in further refining existing standards or preparing new ones for new types of hearing protectors.
Based on the WTO agreement to remove technical barriers to trade, preference in the future is given to international standardization. The ISO should also apply this principle to the standardization of hearing protectors.. The relevant ISO Technical Committee is TC 94 (Personal safety - protective clothing and equipment). Working group 12 (hearing protection) would be responsible for the standardization of hearing protectors. The problem is that no country has accepted the task of secretariat for this group and therefore work has not started. If this ISO working group becomes active in the future, new resources for standardization could come from experts in countries outside Europe.
| Conclusions|| |
The European standards cover nearly all types of hearing protectors. The safety of new models can be assessed against the health and safety requirements of the PPE Directive. This is possible when laboratories work in close coordination with the notified bodies to agree relevant test procedures.
The international standardization in ISO TC 94 WG 12 should be activated soon. As the production and marketing of hearing protectors is globalized, so standards should be the same internationally to avoid unnecessary technical barriers.
| References|| |
|1.||Council Directive 89/686/EEC of 21 December 1989 on the approximation of the laws of the Member States relating to personal protective equipment, Official Journal L 399, 30/12/1989 |
|2.||Council Directive 89/656/EEC of 30 November 1989 on the minimum health and safety requirements for the use by workers of personal protective equipment at the workplace |
|3.||Communication of the Commission concerning assessment of the safety aspects of personal protective equipment with a view to the choice and use thereof (89/C 328/02) |
|4.||Paoli, P., Damien, M. (2000). Third European Survey on Working Conditions , European Foundation for the Improvement of Living and Working Conditions, Office for Official Publications of the European Communities, 2001, Luxembourg |
Finnish Institute of Occupational Health, Topeliuksenkatu 41 a A, FI-00250 Helsinki
Source of Support: None, Conflict of Interest: None